1. Technical Field
The invention relates to loudspeakers, and in particular, to loudspeakers with multiple magnets having polarities aligned in the same direction.
2. Related Art
Loudspeakers convert electrical energy into sound and typically include a diaphragm, a magnet structure, and a voice coil. The magnet structure may include one or more magnets, a core cap, and a shell pot. The shell pot and core cap direct and concentrate a magnetic flux produced by the magnets into an air gap. The voice coil is connected to the diaphragm and is positioned in the air gap. When electrical energy flows into the voice coil, an induced magnetic field is created that interacts with the magnetic flux in the air gap. The voice coil may carry a current in a direction substantially perpendicular to the direction of the magnetic flux produced by the magnet structure, so that the interaction between the voice coil current and the magnetic flux cause oscillation of the voice coil and diaphragm, and in turn, audible sound.
Some loudspeakers may have a magnet structure with in-line magnets polarized in opposite directions, which may result in increased manufacturing complexity. The magnets used in this type of magnet structure may be magnetized prior to assembly, also increasing the manufacturing complexity. Other loudspeakers may use solid magnets to attain a high magnetic flux, but this may result in an undesirable larger profile package and/or a larger mass loudspeaker. Some loudspeakers may have a smaller profile package and/or smaller mass but produce a low magnetic flux and inaccurate voice coil movement, resulting in unsatisfactory performance. Therefore, a need exists for a loudspeaker with a smaller profile package and smaller mass that has a magnet structure that provides an increased magnetic flux and accurate voice coil movement for improved performance.